Lord Kitchener Wants You (1914). This British WWI recruiting poster spawned a lot of famous recruitment posters.

The "Lord Kitchener Wants You" poster debuted in England in 1914 at the start of World War I. It made its first appearance on the cover of the London Opinion and resulted in massive recruitment success. Its most notable legacy went beyond WWI as it would inspire a handful of other notable campaigns.

Uncle Sam Wants You (1917). Inspired by Kitchener, James Montgomery Flagg's work is now the iconic image of Uncle Sam.

Often a Bridesmaid, But Never A Bride (1924). This popular saying is only popular because of a Listerine campaign.

Keep Calm and Carry On (1939). Created by the British government to be distributed in the event of a Nazi invasion, it was never actually displayed at the time. It became newly popular during the 2008 recession.

Think Small (1959). VW launched the modern advertising look we know today -- abandoning text-heavy schmaltz in favor of cool visuals. It is consistently ranked as the top ad of all time.

Heed Their Rising Voices (1960). Litigation over this ad ended four years later, when the Supreme Court decided New York Times v. Sullivan and established a standard for defamation that protected the free press.